Merge pull request #739 from AA-Turner/bootstrap-tomllib

Update the bootstrap guide for ``tomllib``

Author: takluyver

doc/bootstrap.rst

@@ -26,9 +26,18 @@ included in the sdist (or by unzipping it to the correct directory)::
     # Install somewhere else:
     python bootstrap_install.py --installdir /path/to/site-packages dist/flit_core-*.whl
 
-As of version 3.6, flit_core bundles the ``tomli`` TOML parser, to avoid a
-dependency cycle. If you need to unbundle it, you will need to special-case
-installing flit_core and/or tomli to get around that cycle.
+.. note::
+
+   This note only applies if you need to unbundle or unvendor dependencies.
+
+   ``flit_core`` unconditionally bundles the ``tomli`` TOML parser,
+   to avoid a dependency cycle for older versions of Python that don't include
+   the standard library :mod:`tomllib` module.
+
+   The ``tomli`` library is only used on Python 3.10 and older, meaning that
+   if you use Python 3.11 or newer you can simply remove the bundled ``tomli``.
+   Otherwise, you must special-case installing ``flit_core`` and/or ``tomli``
+   to resolve the dependency cycle between the two packages.
 
 After ``flit_core``, I recommend that you get `installer
 <https://pypi.org/project/installer/>`_ set up. You can use